Cargo containers of many forms have been used for transporting land, sea, and air cargo for many years. For example, one type of cargo container is box-like, with at least two side walls, a top, and a flat bottom. Another type of cargo container, commonly in use today, has opposed side walls, a flat top, and a generally rounded bottom. From the side, this type of container resembles a quadrant of a circle, and is shaped in this matter to conform to the shape of one-half of the cargo bay of cargo transport aircraft. These are commonly referred to as “Unit Load Devices” (LD1, LD3). Other types (AMT, AAY) have a rounded top and flat bottom and conform to the shape of the upper cargo bay of cargo transport aircraft. Typically, and regardless of the shape or geometry of the container, one end or side of the cargo container is open for loading and unloading cargo.
Various door closures have been used for opening and closing the open ends of such containers. One type of closure has been a rigid door closure which covers the opening to reduce tampering, to prevent the loss of small items, and to prevent the cargo from being exposed to dirt, moisture, and ultraviolet light. Another type of closures includes the combination of a webbing and a fabric closure. This type of closure has been generally preferred over rigid door closures because it tends to be much lighter and less expensive. The fabric covers have typically been formed from canvas, or vinyl coated nylon or polyester. However, each of these fabrics lacks the durability to withstand physical stresses or lacks resistance to environmental conditions or harsh chemicals common to the transportation industry. For example, exposure to ultraviolet light, diesel and jet fuels, and oils, tends to rapidly degrade such fabric covers. Accordingly, the durability of a cargo cover is ultimately determined by its tear-strength, abrasion resistance, cut-and-stab resistance and ability to withstand environmental and chemical exposure. Otherwise, the product life is very limited and replacement costs are high. Because fabric covers lack the durability to also serve as load retainers, a separate webbing or netting is often required to keep the cargo restrained so that it cannot pass through the covered end or fall out.
In more recent years, as shown in U.S. Pat. No. 5,395,682, fabric closures have been developed of a woven fabric formed of yarns of the fabric are constructed of long-chain extended (ultra-high molecular weight) polyethylene fibers. Such closures have exhibited increased strength and durability, while being considerably lighter than fabrics previously available. More specifically, as shown in U.S. Pat. No. 6,755,232, the fabric closures have been formed as a unitary panel, having web straps spaced apart and attached to the panel for releasable attachment to existing fasteners on the cargo container. In a further improvement to eliminate the need to completely remove the fabric closure from the cargo container for loading and unloading purposes, a fabric closure was developed comprising a single panels, or two panels, having an access opening for loading, unloading, and inspecting cargo, with the loosening or removal of a minimal number of straps and fasteners.